1. Field of the Invention
The present invention relates to a motorcycle or a three-wheeled vehicle which tiltably supports a proximal end portion of a swing arm for pivotally supporting a wheel on a vehicle body frame by way of a pivot shaft and a swing arm pivot structure in the motorcycle or the three-wheeled vehicle.
2. Description of Background Art
In the above-mentioned conventional motorcycle, a structure is known in which a taper bearing is mounted in an inner sleeve of a swing arm with a pivot shaft being fixedly mounted on a vehicle body frame using bolts at a position corresponding to the taper bearing. An inner end portion of the pivot shaft is inserted into an inner peripheral portion of the above-mentioned taper bearing from the outside in the axial direction whereby the pivot shaft which is fixed to the vehicle body frame and the swing arm are mounted for relative rotation therebetween by way of the bearing. For example, see JP-A-59-18080.
However, the above-mentioned conventional structure has several drawbacks. More specifically, since a relatively expensive taper bearing is used between the pivot shaft and the swing arm, a cost is increased. Further, it is difficult to perform an operation to set a preload (pre-pressure) in the thrust direction which is performed at the time of inserting the pivot shaft into the taper bearing while fixedly mounting the pivot shaft to the vehicle body frame using bolts.